Measuring the number of lamellar body particles in amniotic fluid.
We describe a method for determining the number and size distribution of lamellar bodies and compare the results prospectively with other tests for fetal lung maturity: lecithin-sphingomyelin ratio (L/S), phosphatidylglycerol, and fluorescence polarization. The technique uses an electronic particle counter calibrated for a size range of 1.7-7.3 fL. The number of lamellar bodies in amniotic fluid samples varied from 3800-166,000 particles per microliter and correlated strongly with L/S ratio (r = 0.75; N = 144) and fluorescence polarization (r = -0.78; N = 165). Amniotic fluid samples stored for up to 10 days at 4C had stable lamellar body counts (within +/- 11%). Longer storage tended to decrease the counts. Addition of more than 1% (v/v) whole blood significantly decreased the lamellar body counts. This technique shows promise for the rapid assessment of fetal lung maturity.
Ashwood
E R
ER
Department of Pathology, University of Utah School of Medicine, Salt Lake City.
Oldroyd
R G
RG
Palmer
S E
SE
D000653:Amniotic Fluid / Q000032:analysis*; D002138:Calibration; D005325:Fetal Organ Maturity; D005454:Fluorescence Polarization; D006801:Humans; D008168:Lung / Q000196:embryology; D010316:Particle Size; D010713:Phosphatidylcholines / Q000032:analysis; D010715:Phosphatidylglycerols / Q000032:analysis; D010743:Phospholipids / Q000032:analysis*; D011446:Prospective Studies; D013109:Sphingomyelins / Q000032:analysis
D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D010743:Phospholipids; D013109:Sphingomyelins